Various devices are utilized in vehicles to increase efficiency and decrease thermal degradation of components. These devices may include various types of coolers configured to flow two or more fluids therethrough. A first fluid may comprise coolant and a second fluid may comprise a gas. The first and second fluids are prevented from mixing with one another while being permitted to thermally communicate. Based on the application, the cooler may be used to increase power output, decrease surface temperature, decrease emissions, and/or recover thermal energy. However, these coolers are separated from one another, each performing a specific task, which may lead to high manufacturing costs and packaging constraints.
Modern heat exchangers include two or more inlets and corresponding outlets to enable the heat exchangers to receive various intake and exhaust gas flows. As such, a single heat exchanger may function as a charge air cooler (CAC), exhaust gas recirculation (EGR) cooler, and heat recovery device. While these designs may reduce costs and packaging constraints presented by previous models, they do have some drawbacks. For example, the heat exchanger is partitioned for each function it may perform (e.g., CAC, EGR cooler, heat recovery, etc.). However, a volume of each partition is fixed. This prevents the heat exchanger from increasing exposure of intake or exhaust gases to coolant flowing therethrough.
The inventors have identified the above problems and have come up with a solution to solve them. In one example, the issues described above may be addressed by a method comprising adjusting a number of heat exchanger conduits allocated to receive exhaust gas recirculate and correspondingly adjusting a number of heat exchanger conduits allocated to receive exhaust gas by pivoting a flap, and where the heat exchanger conduits are fluidly sealed from one another. In this way, a single heat exchanger may comprise a variable volume to receive different gases.
As one example, the volume of the heat exchanger configured to receive EGR may increase in response to an increased EGR demand. As another example, the volume of heat exchanger configured to receive exhaust gas may increase in response to an increased heat recovery demand. This may be accomplished by actuated the flap of the heat exchanger to direct a gas to a desired number of conduits, where the position of the flap corresponds to a number of conduits configured to receive EGR and exhaust gas. By doing this, a packaging constraint of the heat exchanger is reduced compared to previous attempts. Additionally, a manufacturing cost of the heat exchanger is reduced.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.